Intermedin (Adrenomedullin-2) a novel counter-regulatory peptide in the cardiovascular and renal systems

Intermedin (IMD) is a novel peptide related to calcitonin gene-related peptide (CGRP) and adrenomedullin (AM). Proteolytic processing of a larger precursor yields a series of biologically active C-terminal fragments, IMD1–53, IMD1–47 and IMD8–47. IMD shares a family of receptors with AM and CGRP composed of a calcitonin-receptor like receptor (CALCRL) associated with one of three receptor activity modifying proteins (RAMP). Compared to CGRP, IMD is less potent at CGRP1 receptors but more potent at AM1 receptors and AM2 receptors; compared to AM, IMD is more potent at CGRP1 receptors but less potent at AM1 and AM2 receptors. The cellular and tissue distribution of IMD overlaps in some aspects with that of CGRP and AM but is distinct from both. IMD is present in neonatal but absent or expressed sparsely, in adult heart and vasculature and present at low levels in plasma. The prominent localization of IMD in hypothalamus and pituitary and in kidney is consistent with a physiological role in the central and peripheral regulation of the circulation and water-electrolyte homeostasis. IMD is a potent systemic and pulmonary vasodilator, influences regional blood flow and augments cardiac contractility. IMD protects myocardium from the deleterious effects of oxidative stress associated with ischaemia-reperfusion injury and exerts an anti-growth effect directly on cardiomyocytes to oppose the influence of hypertrophic stimuli. The robust increase in expression of the peptide in hypertrophied and ischaemic myocardium indicates an important protective role for IMD as an endogenous counter-regulatory peptide in the heart.

Supplemental oxygen and hyperbaric treatment at high altitude: Cardiac and respiratory response

Introduction: The most effective treatment for high altitude sickness is prompt descent. However, rapid descent is sometimes impossible and alternative solutions are desirable. Supplemental oxygen at ambient pressure and hyperbaric oxygen in a hyperbaric tent have both been demonstrated to improve symptoms and increase arterial oxygenation (SaO(2)) in those with high altitude sickness; however, their use in combination has not previously been described in a controlled study. Methods and Results: In this feasibility study, the SaO(2) of six healthy, well-acclimatized participants rose from 76.5 to 97.5% at 4900 m and 72.5 to 96.0% at 5700 m following the administration of oxygen via a nasal demand circuit (33 ml of oxygen per pulse) inside a hyperbaric tent (107 mmHg above ambient barometric pressure) (p

Promoting Health Behaviour Change in the Cardiac Patient

The importance of giving patients advice in relation to positive health behaviour change geared towards maximizing physical health must not be overlooked and is an important role of the cardiac nurse in contemporary health care. However, over-reliance on offering advice can often be counter-productive and less likely to achieve effective change. Patients are more likely to make positive health behaviour changes when they self-generate their own solutions to the health issues and problems that they face. In this article, the authors encourage cardiac nurses to embrace a less directive and more facilitative approach to patient health behaviour change in light of the mounting evidence that exists to the effectiveness of motivational interviewing techniques.

Using simulation to assess cardiac first-responder schemes exhibiting stochastic and spatial complexities

A Monte-Carlo simulation-based model has been constructed to assess a public health scheme involving mobile-volunteer cardiac First-Responders. The scheme being assessed aims to improve survival of Sudden-Cardiac-Arrest (SCA) patients, through reducing the time until administration of life-saving defibrillation treatment, with volunteers being paged to respond to possible SCA incidents alongside the Emergency Medical Services. The need for a model, for example, to assess the impact of the scheme in different geographical regions, was apparent upon collection of observational trial data (given it exhibited stochastic and spatial complexities). The simulation-based model developed has been validated and then used to assess the scheme's benefits in an alternative rural region (not a part of the original trial). These illustrative results conclude that the scheme may not be the most efficient use of National Health Service resources in this geographical region, thus demonstrating the importance and usefulness of simulation modelling in aiding decision making.

Assessing quality of life in cardiac rehabilitation: Choosing an appropriate tool

Quality of life is an important outcome for people undergoing cardiac rehabilitation. This paper discusses the difficulties with defining the concept of quality of life and how it might be distinct from the concept of health-related quality of life. Based on a review of the literature, a description is provided of health-related quality of life questionnaires that have been used in cardiac rehabilitation populations. Some criteria for choosing between these questionnaires are then discussed and, finally, a brief discussion is presented of the concept of response shift and how this might influence the assessment of health-related quality of life in a cardiac rehabilitation setting.